I've seen something simular before from other people. So, maybe someone can help me out with this?
I call it 'reverse gradient' but 'gradient on gradient' could also be a good name.
You start with a gradient and then make a design by using a reverse gradient.
Take a look at my nail art and I'll explain:
I started with a sponged gradient (blue to pink).
Then I've placed dots in reverse on index, middle and pinky (pink dots on blue and blue dots on pink).
On the ring finger I placed striping tape on the first gradient. Then I sponged the reverse gradient
(Striping tape design: 1st gradient, rest of the nail: reverse gradient).
Interesting effect isn't it?